Transparent Protein Microtubule Motors with Controllable Velocity and Biodegradability

Slender protein microtube motors with a catalase interior surface are self-propelled in aqueous H₂O₂ by jetting O₂ microbubbles from the open-end terminus. Immobilization of a catalase biocatalyst on the internal wall is achieved using avidin–biotin complexation. It is particularly interesting that the migration of O₂ bubbles in the 1D channel and their subsequent expulsions were clearly visible because the tube walls are transparent. The microtube motor velocity reached a maximum at the optimum pH and temperature of the catalase. Furthermore, the microtubes were digested completely by proteases, showing sufficient biodegradability